The present invention relates to an apparatus for sensing microfilms and which in addition to visible light is provided with a projection lamp radiating infrared-component rays.
Devices for sensing microfilms of the type under consideration are known in the art. In such devices, a beam of rays radiated from the projection lamp is directed through a cold-light mirror to a microfilm platform, then through a projection lens and is finally projected to an image screen or other sensing means, such as a charge coupled device (abbreviated CCD). If such a device is utilized for a mechanical sensing by means of a sensing pin or for scanning with CCD for video transmission then a scanned enlarged microimage must have an enlarged infrared component. On the other hand, the microfilm would be quickly bleached out due to a continuously acting illumination with a great infra-red component.